Beta-thalassemia is a blood disorder that reduces the body's production of hemoglobin. Low levels of hemoglobin lead to a shortage of mature red blood cells and a lack of oxygen in the body. Affected people have anemia, which can cause paleness, weakness, fatigue, and more serious complications. Severe beta-thalassemia is called “thalassemia major” or “Cooley’s anemia.” Thalassemia intermedia is a less severe form. Beta-thalassemia is caused by mutations in the HBBgene and is usually inherited in an autosomal recessive manner. People who have only one HBB gene mutation may have no symptoms or develop mild symptoms, and are said to have thalassemia minor.[1] Treatment depends on the severity in each person and may include transfusions, folic acid supplementation, iron chelation, and/or bone marrow transplantation (the only definitive cure).[2]

The Human Phenotype Ontology (HPO) provides the following list of features that have been reported in people with this condition.
Much of the information in the HPO comes from Orphanet, a European rare disease database. If available, the list includes a rough estimate of how common a feature is (its frequency).
Frequencies are based on a specific study and may not be representative of all studies. You can use the MedlinePlus Medical Dictionary for definitions of the terms below.

Beta-thalassemia major and beta-thalassemia intermedia are usually inherited in an autosomal recessive manner, which means both copies of the HBBgene in each cell have mutations. The parents of a person with an autosomal recessive condition each carry one copy of the mutated gene and are referred to as carriers. When two carriers have children, each child has a 25% (1 in 4) chance to be affected, a 50% (1 in 2) chance to be a carrier like each parent, and a 25% (1 in 4) chance to be unaffected and not be a carrier. Sometimes, people with only one HBB gene mutation in each cell (carriers) do have mild anemia. These people are said to have 'beta-thalassemia minor' or 'beta-thalassemia trait.'[1]

In a small percentage of families, the condition is inherited in an autosomal dominant manner. In these cases, one mutated copy of the gene in each cell is enough to cause the signs and symptoms of beta-thalassemia.[1]

Research helps us better understand diseases and can lead to advances in diagnosis and treatment. This section provides resources to help you learn about medical research and ways to get involved.

Clinical Research Resources

ClinicalTrials.gov lists trials that are studying or have studied Beta-thalassemia. Click on the link to go to ClinicalTrials.gov to read descriptions of these studies.

Please note: Studies listed on the ClinicalTrials.gov website are listed for informational purposes only; being listed does not reflect an endorsement by GARD or the NIH. We strongly recommend that you talk with a trusted healthcare provider before choosing to participate in any clinical study.

Support and advocacy groups can help you connect with other patients and families, and they can provide valuable services. Many develop patient-centered information and are the driving force behind research for better treatments and possible cures. They can direct you to research, resources, and services. Many organizations also have experts who serve as medical advisors or provide lists of doctors/clinics. Visit the group’s website or contact them to learn about the services they offer. Inclusion on this list is not an endorsement by GARD.

Financial Resources

Patient Access Network Foundation (PAN Foundation) has Assistance Programs for those with health insurance who reside in the United States. The disease fund status can change over time, so you may need to check back if funds are not currently available.

These resources provide more information about this condition or associated symptoms. The in-depth resources contain medical and scientific language that may be hard to understand. You may want to review these resources with a medical professional.

Where to Start

You can obtain information on this topic from the Centers for Disease Control and Prevention (CDC). The CDC is recognized as the lead federal agency for developing and applying disease prevention and control, environmental health, and health promotion and education activities designed to improve the health of the people of the United States.

The National Heart, Lung, and Blood Institute (NHLBI) has information on this topic. NHLBI is part of the National Institutes of Health and supports research, training, and education for the prevention and treatment of heart, lung, and blood diseases.

The National Human Genome Research Institute's (NHGRI) website has an information page on this topic. NHGRI is part of the National Institutes of Health and supports research on the structure and function of the human genome and its role in health and disease.

In-Depth Information

Medscape Reference provides information on this topic. You may need to register to view the medical textbook, but registration is free.

The Monarch Initiative brings together data about this condition from humans and other species to help physicians and biomedical researchers. Monarch’s tools are designed to make it easier to compare the signs and symptoms (phenotypes) of different diseases and discover common features. This initiative is a collaboration between several academic institutions across the world and is funded by the National Institutes of Health. Visit the website to explore the biology of this condition.

Online Mendelian Inheritance in Man (OMIM) is a catalog of human genes and genetic disorders. Each entry has a summary of related medical articles. It is meant for health care professionals and researchers. OMIM is maintained by Johns Hopkins University School of Medicine.

Orphanet is a European reference portal for information on rare diseases and orphan drugs. Access to this database is free of charge.

PubMed is a searchable database of medical literature and lists journal articles that discuss Beta-thalassemia. Click on the link to view a sample search on this topic.

Questions sent to GARD may be posted here if the information could be helpful to others. We remove all identifying information when posting a question to protect your privacy. If you do not want your question posted, please let us know.
Submit a new question

My hemoglobin electrophoresis result showed that alpha thalassemia trait is a possibility. My wife is 5 months pregnant. Her result showed that she has beta thalassemia trait. It is the 3rd pregnancy. What is the probability of having an affected baby?
See answer

My partner and I have both been diagnosed with beta-thalassemia minor. What is the likelihood of having a child without beta-thalassemia?
See answer

I've been told that I am a carrier for beta-thalassemia and I have low levels of hemoglobin. Can I donate blood?
See answer